a
FEATURES
Single or Dual-Supply Operation
Excellent Sonic Characteristics
Low Noise: 7 nV/
√
Hz
Low THD: 0.0006%
Rail-to-Rail Output
High Output Current: 50 mA
Low Supply Current: 1.7 mA/Amplifier
Wide Bandwidth: 8 MHz
High Slew Rate: 12 V/ s
No Phase Reversal
Unity Gain Stable
Stable Parameters Over Temperature
APPLICATIONS
Multimedia Audio
Professional Audio Systems
High Performance Consumer Audio
Microphone Preamplifier
MIDI Instruments
GENERAL DESCRIPTION
OUT A 1
–IN A
+IN A
V–
2
3
4
Rail-to-Rail Output
Audio Amplifiers
SSM2275/SSM2475*
PIN CONFIGURATIONS
8-Lead Narrow Body SOIC
(SO-8)
8 V+
14-Lead Narrow Body SOIC
(R-14)
OUT A 1
–IN A 2
+IN A 3
V+ 4
+IN B 5
–IN B 6
OUT B
7
14 OUT D
13 –IN D
12 +IN D
SSM2275
(Not to Scale)
7
6
5
OUT B
–IN B
+IN B
SSM2475
(Not to Scale)
11 V–
10 +IN C
9
8
–IN C
OUT C
8-Lead microSOIC
(RM-8)
OUT A
–IN A
+IN A
V–
1
8
V+
OUT B
–IN B
+IN B
OUT A
–IN A
+IN A
V+
+IN B
–IN B
OUT B
14-Lead TSSOP
(RU-14)
1
14
OUT D
–IN D
+IN D
V–
+IN C
–IN C
OUT C
SSM2275
4
5
SSM2475
7
8
The SSM2275 and SSM2475 use the Butler Amplifier front
end, which combines both bipolar and FET transistors to offer
the accuracy and low noise performance of bipolar transistors
and the slew rates and sound quality of FETs. This product
family includes dual and quad rail-to-rail output audio amplifi-
ers that achieve lower production costs than the industry stan-
dard OP275 (the first Butler Amplifier offered by Analog
Devices). This lower cost amplifier also offers operation from a
single 5 V supply, in addition to conventional
±
15 V supplies.
The ac performance meets the needs of the most demanding au-
dio applications, with 8 MHz bandwidth, 12 V/µs slew rate and
extremely low distortion.
The SSM2275 and SSM2475 are ideal for application in high
performance audio amplifiers, recording equipment, synthesiz-
ers, MIDI instruments and computer sound cards. Where cas-
caded stages demand low noise and predictable performance,
SSM2275 and SSM2475 are a cost effective solution. Both are
stable even when driving capacitive loads.
The ability to swing rail-to-rail at the outputs (see Applications sec-
tion) and operate from low supply voltages enables designers to at-
tain high quality audio performance, even in single supply systems.
The SSM2275 and SSM2475 are specified over the extended
industrial (–40°C to +85°C) temperature range. The SSM2275 is
available in 8-lead plastic DIPs, SOICs, and microSOIC surface-
mount packages. The SSM2475 is available in narrow body
SOICs and thin shrink small outline (TSSOP) surface-mount
packages.
*Protected
by U.S. Patent No. 5,101,126.
8-Lead Plastic DIP
(N-8)
OUT A
–IN A
+IN A
V–
1
2
3
4
(Not to
Scale)
8
7
6
5
V+
OUT B
–IN B
+IN B
SSM2275
REV. A
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norwood. MA 02062-9106, U.S.A.
Tel: 781/329-4700
World Wide Web Site: http://www.analog.com
Fax: 781/326-8703
© Analog Devices, Inc., 1999
SSM2275/SSM2475–SPECIFICATIONS
ELECTRICAL CHARACTERISTICS
(V =
S
15 V, T
A
=
Conditions
25 C, V
CM
= 0 V unless otherwise noted)
Min
Typ
1
1
250
300
5
15
–14
80
80
100
80
14
14.5
100
100
240
120
14.5
14.7
–14
–14.6
–14.3
±
50
±
40
110
105
1.7
1.75
0.0006
12
8
128
8
<1
Max
4
6
400
500
75
125
+14
Units
mV
mV
nA
nA
nA
nA
V
dB
V/mV
V/mV
V/mV
V
V
V
V
V
mA
mA
dB
dB
mA
mA
%
V/µs
MHz
dB
nV/√Hz
pA/√Hz
Parameter
INPUT CHARACTERISTICS
Offset Voltage
Input Bias Current
Input Offset Current
Input Voltage Range
Common-Mode Rejection Ratio
Symbol
V
OS
I
B
I
OS
V
IN
CMRR
–40°C
≤
T
A
≤
+85°C
–40°C
≤
T
A
≤
+85°C
–40°C
≤
T
A
≤
+85°C
V
S
=
±
15 V
–12.5 V
≤
V
CM
≤
+12.5 V
–40°C
≤
T
A
≤
+85°C,
–12.5 V
≤
V
CM
≤
+12.5 V
R
L
= 2 kΩ, –12 V
≤
V
O
≤
+12 V
–40°C
≤
T
A
≤
+85°C
I
L
≤
20 mA
–40°C
≤
T
A
≤
+85°C
I
L
= 20 mA
I
L
= 10 mA
I
L
= 10 mA, –40°C
≤
T
A
≤
+85°C
–40°C
≤
T
A
≤
+85°C
±
2.5 V
≤
V
S
≤ ±18
V
–40°C
≤
T
A
≤
+85°C
V
O
= 0 V
–40°C
≤
T
A
≤
+85°C
R
L
= 10 kΩ, f = 1 kHz, V
O
= 1 V rms
R
L
= 2 kΩ 50 pF
R
L
= 2 kΩ, f =1 kHz
f > 1 kHz
f > 1 kHz
A
VO
OUTPUT CHARACTERISTICS
Output Voltage, High
Output Voltage, Low
V
OH
V
OL
I
SC
Output Short Circuit Current Limit
POWER SUPPLY
Power Supply Rejection Ratio
Supply Current/Amplifier
DYNAMIC PERFORMANCE
Total Harmonic Distortion
Slew Rate
Gain Bandwidth Product
Channel Separation
NOISE PERFORMANCE
Voltage Noise Spectral Density
Current Noise Spectral Density
Specifications subject to change without notice.
±
25
±
17
85
80
–13.5
–14.4
–13.9
±
75
±
80
PSRR
I
SY
2.9
3.0
THD
SR
GBW
CS
e
n
i
n
9
–2–
REV. A
SSM2275/SSM2475
ELECTRICAL CHARACTERISTICS
Parameter
INPUT CHARACTERISTICS
Offset Voltage
Input Bias Current
Input Offset Current
Input Voltage Range
Common-Mode Rejection Ratio
A
VO
OUTPUT CHARACTERISTICS
Output Voltage, High
Output Voltage, Low
V
OS
I
B
I
OS
V
IN
CMRR
(V
S
=
5 V, T
A
=
25 C, V
CM
= 2.5 V unless otherwise noted)
Min
Typ
1
1
250
300
5
15
0.3
85
80
60
50
4.5
4.8
0.6
0.3
0.7
40
1.7
1.75
0.0006
12
6
128
8
<1
Max
4
6
400
500
75
125
4.7
Units
mV
mV
nA
nA
nA
nA
V
dB
dB
V/mV
V/mV
V
V
V
V
V
mA
mA
mA
%
V/µs
MHz
dB
nV/√Hz
pA/√Hz
Symbol
Conditions
–40°C
≤
T
A
≤
+85°C
–40°C
≤
T
A
≤
+85°C
–40°C
≤
T
A
≤
+85°C
+0.8 V
≤
V
CM
≤
+2 V
–40°C
≤
T
A
≤
+85°C
R
L
= 2 kΩ, –0.5 V
≤
V
O
≤
+4.5 V
–40°C
≤
T
A
≤
+85°C
I
L
≤
–15 mA
I
L
≤
–10 mA, –40°C
≤
T
A
≤
+85°C
I
L
≤
–15 mA
I
L
≤
–10 mA
I
L
≤
–10 mA, –40°C
≤
T
A
≤
+85°C
–40°C
≤
T
A
≤
+85°C
V
O
= 0 V
–40°C
≤
T
A
≤
+85°C
R
L
= 10 kΩ, f = 1 kHz, V
O
= 1 V rms
R
L
= 2 kΩ 50 pF
R
L
= 2 kΩ 10 pF
R
L
= 2 kΩ, f =1 kHz
f > 1 kHz
f > 1 kHz
25
20
4.2
4.5
V
OH
V
OL
I
SC
I
SY
1.0
0.5
1.1
Output Short Circuit Current Limit
POWER SUPPLY
Supply Current/Amplifier
DYNAMIC PERFORMANCE
Total Harmonic Distortion
Slew Rate
Gain Bandwidth Product
Channel Separation
NOISE PERFORMANCE
Voltage Noise Spectral Density
Current Noise Spectral Density
Specifications subject to change without notice.
2.9
3.0
THD
SR
GBW
CS
e
n
i
n
REV. A
–3–
SSM2275/SSM2475
Supply Voltage (V
S
) . . . . . . . . . . . . . . . . . . . . . . . . . . . .
±
18 V
Input Voltage (V
IN
) . . . . . . . . . . . . . . . . . . . . . . . . . . . .
±
15 V
Differential Input Voltage
2
. . . . . . . . . . . . . . . . . . . . . . .
±
15 V
Storage Temperature Range . . . . . . . . . . . . 65°C to 150°C
Operating Temperature Range . . . . . . . . . . . 40°C to 85°C
Junction Temperature Range . . . . . . . . . . . . 65°C to 150°C
Lead Temperature Range (Soldering, 60 sec) . . . . . . . 300°C
ESD Susceptibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2,000 V
NOTES
1
Stresses above those listed under Absolute Maximum Ratings may cause perma -
nent damage to the device. This is a stress rating only; the functional operation of
the device at these or any other conditions above those indicated in the operational
sections of this specification is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect device reliability.
2
For supplies less than
±
15 V, the input voltage and differential input voltage
must be less than
±15
V.
ABSOLUTE MAXIMUM RATINGS
1
Package Type
8-Lead Plastic DIP
8-Lead SOIC
8-Lead microSOIC
14-Lead SOIC
14-Lead TSSOP
JA
*
JC
Units
°C/W
°C/W
°C/W
°C/W
°C/W
103
158
206
120
180
43
43
43
36
35
*θ
JA
is specified for the worst case conditions, i.e., for device in socket for DIP
packages and soldered onto a circuit board for surface mount packages.
ORDERING GUIDE
Model
SSM2275P
SSM2275S
SSM2275RM
SSM2475S
SSM2475RU
Temperature
Range
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
Package
Description
8-Lead PDIP
8-Lead SOIC
8-Lead microSOIC
14-Lead SOIC
14-Lead TSSOP
Package
Options
N-8
SO-8
RM-8
R-14
RU-14
CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily
accumulate on the human body and test equipment and can discharge without detection.
Although the SSM2275/SSM2475 features proprietary ESD protection circuitry, permanent
damage may occur on devices subjected to high energy electrostatic discharges. Therefore, proper
ESD precautions are recommended to avoid performance degradation or loss of functionality.
WARNING!
ESD SENSITIVE DEVICE
100
V
S
= 2.5V
R
L
= 2k
C
L
= 10pF
225
100
80
60
PHASE – Degrees
GAIN – dB
V
S
= 2.5V
R
L
= 600
C
L
= 10pF
225
180
135
PHASE – Degrees
80
60
GAIN – dB
40
180
135
90
40
20
0
90
45
0
20
0
–20
–40
10
45
0
–45
–90
10M 40M
–20
–40
10
–45
–90
10M 40M
100
1k
10k
100k
FREQUENCY – Hz
1M
100
1k
10k
100k
FREQUENCY – Hz
1M
Figure 1. Phase/Gain vs. Frequency
Figure 2. Phase/Gain vs. Frequency
–4–
REV. A
Typical Characteristics–SSM2275/SSM2475
100
80
60
GAIN – dB
V
S
= 15V
R
L
= 2k
C
L
= 10pF
225
180
135
PHASE – Degrees
VOLTAGE NOISE DENSITY – nV/
Hz
60
V
S
=
T
A
=
50
15V
25 C
40
40
20
0
90
45
0
30
20
–20
–40
10
–45
–90
10M 40M
10
100
1k
10k
100k
FREQUENCY – Hz
1M
0
10
100
1k
FREQUENCY – Hz
10k
100k
Figure 3. Phase/Gain vs. Frequency
Figure 6. SSM2275 Voltage Noise Density (Typical)
100
80
60
GAIN – dB
V
S
= 15V
R
L
= 600
C
L
= 10pF
225
180
135
PHASE – Degrees
140
120
100
V
S
=
T
A
=
15V
25 C
40
20
0
COMMON MODE REJECTION – dB
90
45
0
80
60
40
–20
–40
10
–45
–90
10M 40M
20
0
100
100
1k
10k
100k
FREQUENCY – Hz
1M
1k
10k
1M
FREQUENCY – Hz
10M
30M
Figure 4. Phase/Gain vs. Frequency
Figure 7. Common-Mode Rejection vs. Frequency
2.0
1.8
CURRENT NOISE DENSITY – pA/
Hz
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
10
V
S
=
T
A
=
15V
25 C
POWER SUPPLY REJECTION – dB
140
120
100
V
S
=
T
A
=
15V
25 C
80
60
40
20
0
100
100
1k
FREQUENCY – Hz
10k
1k
10k
FREQUENCY – Hz
1M
10M
Figure 5. SSM2275 Current Noise Density vs. Frequency
Figure 8. Power Supply Rejection vs. Frequency
REV. A
–5–